The latest controversy — and the operation that arguably has been studied the most in randomized clinical trials — is surgery for a torn meniscus, a sliver of cartilage that acts as a shock absorber in the knee. It’s a condition that often afflicts middle-aged and older people, simply as a consequence of degeneration that can occur with age and often accompanying osteoarthritis. The result can be a painful, swollen knee. Sometimes the knee can feel as if it catches or locks. So why not do an operation to trim or repair the torn tissue?
About 400,000 middle-aged and older Americans a year have meniscus surgery. And here is where it gets interesting. Orthopedists wondered if the operation made sense because they realized there was not even a clear relationship between knee pain and meniscus tears. When they did M.R.I.scans on knees of middle-aged people, they often saw meniscus tears in people who had no pain. And those who said their knee hurt tended to have osteoarthritis, which could be the real reason for their pain.